1. Field of the Invention
This invention relates to fluid-solids contact devices wherein a fluid (gas or solid) is contacted with particulate solids in a tank to effect a change in the composition of the fluid. More particularly, the invention concerns such fluid-solids contacting devices having an improved fluid distributor.
2. Statement of the Prior Art
Fluid-solids contacting devices are well known wherein a gas or liquid is contacted with particulate solids for the purpose of altering the characteristics of the gas or liquid. Typical examples for gas contacting include: cleaning exhaust airstreams by removing contaminants; cleaning storage tank vent gases; process vents; treating sewage gas vent streams; treating laboratory hood exhaust streams; treating the exhaust gases from vacuum pumps; dehydrating gaseous streams, particularly airstreams. For these gas-solids contact devices, the treatment solids may be particulate activated carbon; silica gel; activated alumina; ion exchange resins; various coalescing fibrous solids and the like.
Typical liquid-solids contacting installations include: sewage treatments; industrial waste waters; solvent streams; laboratory waste streams; separator runoff streams; scrubber wastes; plant and transportation spills; electroplating baths; recycled water; potable water; wash water. The particulate solids may be activated carbon; silica gel; activated alumina; molecular sieves; ion exchange resins; coalescing fibers.
Disposable or rechargeable devices are known wherein a tank, frequently a conventional metal drum (e.g., 55 gallons capacity) is employed as a tank for the particulate solids. The fluid (gas or liquid) is introduced and required to pass through a bed of the particulate solids for treatment. The treated fluid is recovered at the other end of the bed of particulate solids as a fluid stream. According to the prior art, such tanks employ a distributor plate in some cases to support the particulate solids bed and in other cases employ a supporting bed of inert solids such as gravel or sand to serve as a fluid distributing member to distribute the impact velocity component of the inlet fluid or withdrawn fluid.
The use of such distributor plates and supporting inert solids beds restricts the inventory of particulate solids which can be maintained in the tank. Hence such device must be replaced or recharged frequently. The recharging of such tanks is a cumbersome operation since the perforated membrane must be cleaned and reinstalled; or the inert solids must be discarded, or removed, cleaned, recovered and replaced. All of the prior art disposable or rechargeable fluids-solids contacting devices would be improved by minimizing channeling within the bed of particulate solids.
Accordingly there is a need for an improved fluid-solids contact device which has a longer operating life and hence requires fewer replacements. There is a need for a fluid-solids contact device with improved fluid flow distribution and accompanying reduction in the fluid pressure drop through the solids bed.
A fluid-solids treatment device which can be easily refilled without requiring special treatment of screens or inert solids is desirable.